Correlations between pathogen concentration and fecal indicator marker genes in beach environments

Area of Science:

• Environmental microbiology
• Molecular biology
• Public health

Background:

• Assessing microbial contamination in recreational waters is crucial for public health.
• Fecal indicator bacteria (FIB) are commonly used to infer contamination, but their reliability can vary.
• Potential pathogens may behave differently in various environmental matrices like water, sand, and sediment.

Purpose of the Study:

• To quantify potential pathogen concentrations in beach water, sand, and sediment.
• To investigate the correlations between potential pathogen markers and FIB genetic markers across different sample types.
• To evaluate the suitability of FIB markers for monitoring beach environments.

Main Methods:

• Microfluidic quantitative PCR (MFQPCR) was employed to analyze samples.
• Nineteen different pathogen marker genes were examined.
• Beach water, sand, and sediment samples from Duluth, MN were analyzed.

Main Results:

• The eaeA gene (Escherichia coli) and plc gene (Clostridium perfringens) were the most frequently detected pathogen markers.
• Positive correlations between potential pathogens and FIB markers were found in beach water and wastewater.
• Correlations were less frequent in sand and sediment samples.

Conclusions:

• The behavior of potential pathogens and FIB markers differs between water and sand/sediment matrices.
• Careful selection of FIB marker genes is necessary for accurate water and sand quality monitoring.
• Environmental factors influence the relationship between pathogens and indicators.